I don't want to discourage but you should always use list variables in case of storing the same kind information for different objects. For example, a variable like {rank.%player%} is only specific for 1 player (not to mention that using player instead of uuid of player isn't good for cases of storing long living data). If you use {rank::%uuid of player%} you can loop the variable, compare the ranks, clear the whole list if necessary and make a leaderboard of the var (although a leaderboard isn't useful in this case). As for the argument of keeping things simple, if you intention is to make it easy to understand for others than its counterproductive. If someone truly cannot understand lists, using them will help him do so and encourage him to learn. On the other hand, not doing so and ignoring the existence of lists will make the reader ignorant of lists. This logic applies not only to lists, but to coding techniques and the likes.
Sorry for the long message but just wanted to clear this out, as this mistake is made often